package com.study.结构型模式.外观模式;

public class Stereo {

    private Stereo(){}

    private static final class Instance{
        private static final Stereo instance = new Stereo();
    }

    public static Stereo getInstance(){
        return Instance.instance;
    }


    public void on(){
        System.out.println("Stereo  on");
    }

    public void off(){
        System.out.println("Stereo  off");
    }

    public void up(){
        System.out.println("Stereo  up");
    }

    public void down(){
        System.out.println("Stereo  down");
    }
}
